Orexins excite the dorsal lateral geniculate nucleus neurons in pigmented and albino rats

• Autorzy: Chrobok L. , Palus K. , Lawandowski M.H.
• Języki publikacji: EN

Abstrakty

EN

BACKGROUND AND AIMS: The dorsal lateral geniculate nucleus (dLGN) is the relay thalamic nucleus for the visual pathway. It consists of the thalamo-cortical neurons that convey visual information from the retina to the occipital cortex. Orexins (OXA and OXB) are two hypothalamic neuropeptides involved in many physiological processes like the control of the sleep/wake state, feeding or arousal. Orexinergic system of the lateral hypothalamus is considered to be the major non-specific system and its fibers can be found throughout the whole brain. Moreover, orexin receptors are known to be located on the dLGN neurons. The aim of our study was to evaluate effects of orexins on the neuronal activity and membrane potential of the dLGN in three different rat strains: pigmented Long Evans rats (LE), albino Wistar (WIS) and Sprague Dawley rats (SD) METHODS: The whole-cell in vitro patch clamp technique was used on the acute (250 µm thick) brain slices derived from 13–18 days old male rats. Majority of the registrations was performed in the presence of tetrodotoxin (0.5 µM), to isolate the investigated neuron. OXA and OXB (200 nM) were applied by bath perfusion. All the tested cells were filled with biocytin and visualised under confocal microscope. RESULTS: Our results indicate that the most of dLGN neurons was affected by orexins. We observed the increase in the firing rate or the direct depolarisation after the peptide application and this result was repetitive in all three rat strains (LE: 8.3±2.4 mV and 14.1±3.3 mV; WIS: 9.4±1.9 mV and 8.0±1.5 mV; SD: 8.4±1.3 mV and 8.0±1.7 mV; for OXA and OXB, respectively). However, our results are on the contrary to other studies claiming dLGN insensitivity to orexins. CONCLUSIONS: This study sheds new light on the role of orexins in the mammalian visual pathway. To our knowledge, we are the first to suggest the orexinergic modulation of the primary sensory (“first order”) thalamic nuclei. This work is supported by NSC grant OPUS V: 2013/09/B/ NZ4/00541

• Wydawca: -
• Czasopismo: Acta Neurobiologiae Experimentalis
• Rocznik: 2015
• Tom: 75
• Numer: Supl.
• Opis fizyczny: p.S109-S110

Twórcy

autor

Chrobok L.

• Department of Neurophysiology and Chronobiology, Jagiellonian University, Krakow, Poland

autor

Palus K.

• Department of Neurophysiology and Chronobiology, Jagiellonian University, Krakow, Poland

autor

Lawandowski M.H.

• Department of Neurophysiology and Chronobiology, Jagiellonian University, Krakow, Poland